#define LIN_OUT 1 // Include the resources for the linear output function
#define Adafruit_ZeroFFT 256 // Sets the ZeroFFT length to 256 points
#define MERR 10 // Number of error values to store in elist[MERR]
#define PID_ON 1 // Use PID feedback or not
#define TRI_PERIOD 100 // Half-period of triangle wave in loops
#define F_BLACKMAN 0.02463994238109641755656975202572 // Osillation freq. for Blackman filter
#define ARM_MATH_CM0PLUS
#include <arm_common_tables.h>
#include <arm_math.h>
#include <Adafruit_ZeroFFT.h>
#include <SPI.h>
// Photodiode array variables
byte CLKpin = 4; // Arduino pin delivering the clock pulses to pin 3 (CLK) of the TSL1402R byte SIpin = 5; // Arduino pin delivering the SI (serial-input) pulse to pin 2 of the TSL1402R byte AOpin0 = A1; // Arduino pin connected to pin 4 (analog output 1)of the TSL1402R byte AOpin1 = A2; // Arduino pin connected to pin 8 (analog output 2)of the TSL1402R
// Variables for determining the displacment from the ZeroFFT
int maxindex; // Index of the maximum of the ZeroFFT float maxvalue; // For comparing the values of the ZeroFFT to find the global maximum double kmax; // Spatial wavenumber corresponding to the dominant fringe modulation Fourier component float Am; // Real part of Fourier coefficent corresponding to kmax float Bm; // Imag part of Fourier coefficent corresponding to kmax float theta; // Phase angle of Fourier transform at kmax float preTheta = 0; // Storage for previous value of phase angle int Nwrap = 0; // Number of phase wraps float displacement; // Displacement in nanometers float predisplacement; // Storage for initial value of displacement int w = 0; int prevw = 0; int wdiff = 0;
// PID Variables
unsigned long lastTime; double Output=0; // Output value for PID (voltage to the piezoelectric actuator (in millivolts)) double Setpoint; // Desired value of displacement (in nm) double kp = 0 / 1; // 0 proportional gain for PID double ki = 2/1; // (1000 / (138.5)) integral gain for PID //double ki = 2/ 1; // (1000 / (138.5)) integral gain for PID double kd = 0/ 100; // 0 derivative gain for PID double error; // Error signal; difference between setpoint and displacement (in nm) double preverror; // Stores previous value of error for derivative control float esum; // Integral of error signal over time float D; // Derivative of error signal unsigned long time0 = 0; // Used in calculating the derivative term float MSerror = 0; // Mean squared error float RMSerror = 0; // Root mean squared error float elist[MERR];// Array of last MERR error values int jerr = 0; // index of integral error term float runningRMSerror = 0; // RMS error calc'd from elist
float m = 0; // extra variables for one time calculations float pchange = 0; float lastp = 0; float k = 1; int p = 1; float M = 0; //int switchtime = 1200; // Time (in ms) between Setpoint switches
void setup() { Serial.begin(9600); // Initialize serial interface to computer (i.e. serial monitor or plotter) INIT_PHOTO(); // Initialize the photodiode array READ_PHOTO(); // Read the photodiode array DO_ZeroFFT(); // Calculate the ZeroFFT of the photodiode array data FIND_PEAK_INDEX(); // Determine index of peak in ZeroFFT KMAX(); // Calculate spatial wavevector of the interferogram INIT_PHOTO(); // Maybe could be replaced by START_EXPOSURE() READ_PHOTO(); // Read photodiode again in preparation for next step PHASE_ANGLE(); // Calculate the complex phase angle of the ZeroFFT peak DISPLACEMENT(); // Calculate the displacement from the phase angle predisplacement = displacement; // Save the initial displacement corresponding to center of PZT range Setpoint = 0; // Define the initial setpoint delay(100); // Allow things to settle before beginning loop START_EXPOSURE(); // Turn on the photodiode array and begin integrating }
void loop() { KMAX(); // Calculate kmax from previous cycle's ZeroFFT READ_PHOTO(); // Read photodiode array PHASE_ANGLE(); // Calculate complex phase angle corresponding to kmax peak WRAPPING(); // Determine if a phase wrap occurred DISPLACEMENT(); // Calculate the displacement from the unwrapped phase DO_ZeroFFT(); // Calculate the ZeroFFT of the photodiode array data FIND_PEAK_INDEX(); // Determine index of peak in ZeroFFT //OSC_SET(); // Oscillate the setpoint up and down PID_LOOP(); // Perform feedback to follow the setpoint (if PID_ON is set to 1) //OSC_DAC(); // Send an oscillating voltage to the DAC //TRI_DAC(); // Send a triangular wave voltage to the DAC START_EXPOSURE(); // Turn on the photodiode array and begin integrating for next cycle SERIAL_PRINT(); // Print some outputs to the serial USB port }
// Photodiode functions
void ClockPulse() { // For sending clock pulses during reading of photodiode delayMicroseconds(1); digitalWrite(CLKpin, HIGH); digitalWrite(CLKpin, LOW); }
void INIT_PHOTO() { // Intialization of photodiode // Initialize two Arduino pins as digital output: pinMode(CLKpin, OUTPUT); pinMode(SIpin, OUTPUT); // To set up the ADC, first remove bits set by Arduino library, then choose
for ( int i = 0; i < 14; i++ ) { digitalWrite(i, LOW);#define LIN_OUT 1 // Include the resources for the linear output function #define Adafruit_ZeroFFT 256 // Sets the ZeroFFT length to 256 points #define MERR 10 // Number of error values to store in elist[MERR] #define PID_ON 1 // Use PID feedback or not #define TRI_PERIOD 100 // Half-period of triangle wave in loops #define F_BLACKMAN 0.02463994238109641755656975202572 // Osillation freq. for Blackman filter #define ARM_MATH_CM0PLUS #include <arm_common_tables.h> #include <arm_math.h> #include <Adafruit_ZeroFFT.h> #include <SPI.h> // Photodiode array variables byte CLKpin = 4; // Arduino pin delivering the clock pulses to pin 3 (CLK) of the TSL1402R byte SIpin = 5; // Arduino pin delivering the SI (serial-input) pulse to pin 2 of the TSL1402R byte AOpin0 = A1; // Arduino pin connected to pin 4 (analog output 1)of the TSL1402R byte AOpin1 = A2; // Arduino pin connected to pin 8 (analog output 2)of the TSL1402R // Variables for determining the displacment from the ZeroFFT int maxindex; // Index of the maximum of the ZeroFFT float maxvalue; // For comparing the values of the ZeroFFT to find the global maximum double kmax; // Spatial wavenumber corresponding to the dominant fringe modulation Fourier component float Am; // Real part of Fourier coefficent corresponding to kmax float Bm; // Imag part of Fourier coefficent corresponding to kmax float theta; // Phase angle of Fourier transform at kmax float preTheta = 0; // Storage for previous value of phase angle int Nwrap = 0; // Number of phase wraps float displacement; // Displacement in nanometers float predisplacement; // Storage for initial value of displacement int w = 0; int prevw = 0; int wdiff = 0; // PID Variables unsigned long lastTime; double Output=0; // Output value for PID (voltage to the piezoelectric actuator (in millivolts)) double Setpoint; // Desired value of displacement (in nm) double kp = 0 / 1; // 0 proportional gain for PID double ki = 2/1; // (1000 / (138.5)) integral gain for PID //double ki = 2/ 1; // (1000 / (138.5)) integral gain for PID double kd = 0/ 100; // 0 derivative gain for PID double error; // Error signal; difference between setpoint and displacement (in nm) double preverror; // Stores previous value of error for derivative control float esum; // Integral of error signal over time float D; // Derivative of error signal unsigned long time0 = 0; // Used in calculating the derivative term float MSerror = 0; // Mean squared error float RMSerror = 0; // Root mean squared error float elist[MERR];// Array of last MERR error values int jerr = 0; // index of integral error term float runningRMSerror = 0; // RMS error calc'd from elist float m = 0; // extra variables for one time calculations float pchange = 0; float lastp = 0; float k = 1; int p = 1; float M = 0; //int switchtime = 1200; // Time (in ms) between Setpoint switches void setup() { Serial.begin(9600); // Initialize serial interface to computer (i.e. serial monitor or plotter) INIT_PHOTO(); // Initialize the photodiode array READ_PHOTO(); // Read the photodiode array DO_ZeroFFT(); // Calculate the ZeroFFT of the photodiode array data FIND_PEAK_INDEX(); // Determine index of peak in ZeroFFT KMAX(); // Calculate spatial wavevector of the interferogram INIT_PHOTO(); // Maybe could be replaced by START_EXPOSURE() READ_PHOTO(); // Read photodiode again in preparation for next step PHASE_ANGLE(); // Calculate the complex phase angle of the ZeroFFT peak DISPLACEMENT(); // Calculate the displacement from the phase angle predisplacement = displacement; // Save the initial displacement corresponding to center of PZT range Setpoint = 0; // Define the initial setpoint delay(100); // Allow things to settle before beginning loop START_EXPOSURE(); // Turn on the photodiode array and begin integrating } void loop() { KMAX(); // Calculate kmax from previous cycle's ZeroFFT READ_PHOTO(); // Read photodiode array PHASE_ANGLE(); // Calculate complex phase angle corresponding to kmax peak WRAPPING(); // Determine if a phase wrap occurred DISPLACEMENT(); // Calculate the displacement from the unwrapped phase DO_ZeroFFT(); // Calculate the ZeroFFT of the photodiode array data FIND_PEAK_INDEX(); // Determine index of peak in ZeroFFT //OSC_SET(); // Oscillate the setpoint up and down PID_LOOP(); // Perform feedback to follow the setpoint (if PID_ON is set to 1) //OSC_DAC(); // Send an oscillating voltage to the DAC //TRI_DAC(); // Send a triangular wave voltage to the DAC START_EXPOSURE(); // Turn on the photodiode array and begin integrating for next cycle SERIAL_PRINT(); // Print some outputs to the serial USB port } // Photodiode functions void ClockPulse() { // For sending clock pulses during reading of photodiode delayMicroseconds(1); digitalWrite(CLKpin, HIGH); digitalWrite(CLKpin, LOW); } void INIT_PHOTO() { // Intialization of photodiode // Initialize two Arduino pins as digital output: pinMode(CLKpin, OUTPUT); pinMode(SIpin, OUTPUT); // To set up the ADC, first remove bits set by Arduino library, then choose for ( int i = 0; i < 14; i++ ) { digitalWrite(i, LOW); } // Clock out any existing SI pulse through the ccd register: for (int i = 0; i < 260; i++) { ClockPulse(); } // Create a new SI pulse and clock out that same SI pulse through the sensor register: digitalWrite(SIpin, HIGH); ClockPulse(); digitalWrite(SIpin, LOW); for (int i = 0; i < 260; i++) { ClockPulse(); } } void READ_PHOTO() { // Read the photodiode // Stop the ongoing integration of light quanta from each photodiode by clocking in a SI pulse // into the sensors register: digitalWrite(SIpin, HIGH); ClockPulse(); digitalWrite(SIpin, LOW); // Next, read all 256 pixels in parallel. Store the result in the array. Each clock pulse // causes a new pixel to expose its value on the two outputs: for (int i = 0; i < 128; i++) { delayMicroseconds(20); // We add a delay to stabilize the AO output from the sensor ZeroFFT_input[2 * i] = analogRead(AOpin0); // Output of first half of photodiode array ZeroFFT_input[2 * i + 1] = 0; // Store zero in the "imaginary" part of the array ZeroFFT_input[2 * i + 256] = analogRead(AOpin1); // Output of second half of photodiode array ZeroFFT_input[2 * i + 257] = 0; // Store zero in the "imaginary" part of the array ClockPulse(); } // Next, AGAIN stop the ongoing integration of light quanta from each photodiode // by clocking in a SI pulse. This is necessary because during the readout operation, // the 18th clock pulse starts the integration of light intensity again. // This way we can turn on the integration when we want using the START_EXPOSURE() command. digitalWrite(SIpin, HIGH); ClockPulse(); digitalWrite(SIpin, LOW); // The photodiode remains OFF after this function completes. // Call START_EXPOSURE() to turn on the photodiode array and begin integrating. } void START_EXPOSURE() { // The photodiode array starts integrating once 18 clock pulses have passed. // At that time, the photodiodes are once again active. We clock out the SI pulse through // the 256 bit register in order to be ready to halt the ongoing measurement at our will // (by clocking in a new SI pulse): // To be used after all calculations are finished, but // before the next photodiode read operation. for (int i = 0; i < 260; i++) { if (i == 18) { // Now the photodiodes goes active.. // An external trigger can be placed here } ClockPulse(); } // Uncomment the next line to increase the integration time. //delay(15);// <-- Add 15 ms integration time } //Calculation Functions void DO_ZeroFFT() { // Performs the ZeroFFT ZeroFFT_reorder(); // Reorders the ZeroFFT_input array to allow the ZeroFFT_run() command to be used ZeroFFT_run(); // This is the function that actually does the ZeroFFT ZeroFFT_mag_lin(); // Produces a variable ZeroFFT_lin_out that contains the absolute values of the ZeroFFT, 128 elements long. } void FIND_PEAK_INDEX() { // Finds the index of the major peak in the ZeroFFT maxvalue = 0; maxindex = 0; for (int i = 5; i < 128; i++) // Go through each element of the ZeroFFT (skip the DC peak) { if (ZeroFFT_lin_out[i] > maxvalue) // If the magnitude is larger than the previously seen maximum... { maxvalue = ZeroFFT_lin_out[i]; // ...store the new max... maxindex = i; // ...and the index at which it occurs. } } } void KMAX() { // Calculates the spatial wavevector of the interferogram corresponding // to the peak in the ZeroFFT. kmax = 2 * PI / 256 * maxindex; } void PHASE_ANGLE() { // Calculates the complex phase angle of the ZeroFFT peak // NOTE: This function must be called BEFORE the ZeroFFT is calculated. Am = 0; Bm = 0; for (int i = 0; i < 256; i++) // Calculate the real and imag Fourier components { Am = Am + float ((ZeroFFT_input[2 * i]) * cos(kmax * i)); //magnitude of real part Bm = Bm + float ((ZeroFFT_input[2 * i]) * sin(kmax * i)); //magnitude of imaginary part } theta = atan2(Bm, Am); // Complext phase angle (in radians) } void WRAPPING() { // Determines if a phase wrap/unwrap occured and accounts for it if ((preTheta ) > (0.5 * PI) && (theta) < (-0.7 * PI)) { // Compare the previous theat to the current theta to see if a wrap occured. Nwrap = Nwrap + 1; // If so, add 1 to the number of wraps. } if ((preTheta) < (-0.7 * PI) && (theta) > (0.5 * PI)) { // If an unwrap occured (a phase wrap in the other direction)... Nwrap = Nwrap - 1; // ...then subtract 1 from the number of wraps. } preTheta = theta; // Store the current theta for the next cycle } void DISPLACEMENT() { // Calculate the displacement after the phase angle is determined m = 2 * PI * Nwrap; //M = theta + m; displacement = ((-(theta + m) * 632) * (1 / (4 * PI)) * (1 / sqrt(2))) - predisplacement; //displacement = ((-(theta + m) * 632) * (1 / (4 * PI)) * (0.80)) - predisplacement; } // Servo Functions void PID_LOOP() { // Performs feedback signal for PID control error = Setpoint - displacement; // Store the current error signal; overwrite if necessary if( jerr >= MERR ){ jerr = 0; } elist[jerr] = error; jerr++; // Calculate the running RMS error runningRMSerror = 0; for(int i=0; i<MERR; i++) { runningRMSerror += pow(elist[i],2); } runningRMSerror = sqrt(runningRMSerror/MERR); // Calculate the mean-squared and root-mean-square errors over all time MSerror = (k - 1) / k * MSerror + pow(error, 2) / k; RMSerror = sqrt(MSerror); k = k + 1; // Integral of error over all time esum = esum + error; // Derivative of error time0 = millis(); D = (error - preverror) / (time0 - lastTime); // The feedback signal (in millivolts) // The minus signs are to make sure the piezo moves in the right direction Output = -(kp * error) -(ki * esum) -(kd * D); // Send the feedback to the DAC if PID_ON is 1 /*if (PID_ON) { val = offset + Output; val = max(val, 0); // Constrain the output voltage so that is stays in range val = min(val, 4096); DAC_TRANSFER(); } // Save the current time and error for calc'ing the derivative next cycle lastTime = time0; preverror = error;*/ } void SERIAL_PRINT(){ Serial.print(displacement); Serial.print(" , "); Serial.println(millis()); Serial.print(" ") ;}
// Clock out any existing SI pulse through the ccd register: for (int i = 0; i < 260; i++) { ClockPulse(); } // Create a new SI pulse and clock out that same SI pulse through the sensor register: digitalWrite(SIpin, HIGH); ClockPulse(); digitalWrite(SIpin, LOW); for (int i = 0; i < 260; i++) { ClockPulse(); } }
void READ_PHOTO() { // Read the photodiode
// Stop the ongoing integration of light quanta from each photodiode by clocking in a SI pulse // into the sensors register: digitalWrite(SIpin, HIGH); ClockPulse(); digitalWrite(SIpin, LOW);
// Next, read all 256 pixels in parallel. Store the result in the array. Each clock pulse // causes a new pixel to expose its value on the two outputs: for (int i = 0; i < 128; i++) { delayMicroseconds(20); // We add a delay to stabilize the AO output from the sensor ZeroFFT_input[2 * i] = analogRead(AOpin0); // Output of first half of photodiode array ZeroFFT_input[2 * i + 1] = 0; // Store zero in the "imaginary" part of the array ZeroFFT_input[2 * i + 256] = analogRead(AOpin1); // Output of second half of photodiode array ZeroFFT_input[2 * i + 257] = 0; // Store zero in the "imaginary" part of the array ClockPulse(); }
// Next, AGAIN stop the ongoing integration of light quanta from each photodiode // by clocking in a SI pulse. This is necessary because during the readout operation, // the 18th clock pulse starts the integration of light intensity again. // This way we can turn on the integration when we want using the START_EXPOSURE() command. digitalWrite(SIpin, HIGH); ClockPulse(); digitalWrite(SIpin, LOW);
// The photodiode remains OFF after this function completes. // Call START_EXPOSURE() to turn on the photodiode array and begin integrating. }
void START_EXPOSURE() { // The photodiode array starts integrating once 18 clock pulses have passed. // At that time, the photodiodes are once again active. We clock out the SI pulse through // the 256 bit register in order to be ready to halt the ongoing measurement at our will // (by clocking in a new SI pulse): // To be used after all calculations are finished, but // before the next photodiode read operation. for (int i = 0; i < 260; i++) { if (i == 18) { // Now the photodiodes goes active.. // An external trigger can be placed here } ClockPulse(); } // Uncomment the next line to increase the integration time. //delay(15);// <-- Add 15 ms integration time }
//Calculation Functions
void DO_ZeroFFT() { // Performs the ZeroFFT ZeroFFT_reorder(); // Reorders the ZeroFFT_input array to allow the ZeroFFT_run() command to be used ZeroFFT_run(); // This is the function that actually does the ZeroFFT ZeroFFT_mag_lin(); // Produces a variable ZeroFFT_lin_out that contains the absolute values of the ZeroFFT, 128 elements long. }
void FIND_PEAK_INDEX() { // Finds the index of the major peak in the ZeroFFT maxvalue = 0; maxindex = 0; for (int i = 5; i < 128; i++) // Go through each element of the ZeroFFT (skip the DC peak) { if (ZeroFFT_lin_out[i] > maxvalue) // If the magnitude is larger than the previously seen maximum... { maxvalue = ZeroFFT_lin_out[i]; // ...store the new max... maxindex = i; // ...and the index at which it occurs. } } }
void KMAX() { // Calculates the spatial wavevector of the interferogram corresponding // to the peak in the ZeroFFT. kmax = 2 * PI / 256 * maxindex; }
void PHASE_ANGLE() { // Calculates the complex phase angle of the ZeroFFT peak // NOTE: This function must be called BEFORE the ZeroFFT is calculated. Am = 0; Bm = 0; for (int i = 0; i < 256; i++) // Calculate the real and imag Fourier components { Am = Am + float ((ZeroFFT_input[2 * i]) * cos(kmax * i)); //magnitude of real part Bm = Bm + float ((ZeroFFT_input[2 * i]) * sin(kmax * i)); //magnitude of imaginary part } theta = atan2(Bm, Am); // Complext phase angle (in radians) }
void WRAPPING() { // Determines if a phase wrap/unwrap occured and accounts for it if ((preTheta ) > (0.5 * PI) && (theta) < (-0.7 * PI)) { // Compare the previous theat to the current theta to see if a wrap occured. Nwrap = Nwrap + 1; // If so, add 1 to the number of wraps. } if ((preTheta) < (-0.7 * PI) && (theta) > (0.5 * PI)) { // If an unwrap occured (a phase wrap in the other direction)... Nwrap = Nwrap - 1; // ...then subtract 1 from the number of wraps. } preTheta = theta; // Store the current theta for the next cycle }
void DISPLACEMENT() { // Calculate the displacement after the phase angle is determined m = 2 * PI * Nwrap; //M = theta + m; displacement = ((-(theta + m) * 632) * (1 / (4 * PI)) * (1 / sqrt(2))) - predisplacement; //displacement = ((-(theta + m) * 632) * (1 / (4 * PI)) * (0.80)) - predisplacement; }
// Servo Functions
void PID_LOOP() { // Performs feedback signal for PID control error = Setpoint - displacement;
// Store the current error signal; overwrite if necessary if( jerr >= MERR ){ jerr = 0; } elist[jerr] = error; jerr++;
// Calculate the running RMS error runningRMSerror = 0; for(int i=0; i<MERR; i++) { runningRMSerror += pow(elist[i],2); } runningRMSerror = sqrt(runningRMSerror/MERR);
// Calculate the mean-squared and root-mean-square errors over all time MSerror = (k - 1) / k * MSerror + pow(error, 2) / k; RMSerror = sqrt(MSerror); k = k + 1;
// Integral of error over all time esum = esum + error;
// Derivative of error time0 = millis(); D = (error - preverror) / (time0 - lastTime);
// The feedback signal (in millivolts) // The minus signs are to make sure the piezo moves in the right direction Output = -(kp * error) -(ki * esum) -(kd * D);
// Send the feedback to the DAC if PID_ON is 1 /*if (PID_ON) { val = offset + Output; val = max(val, 0); // Constrain the output voltage so that is stays in range val = min(val, 4096); DAC_TRANSFER(); }
// Save the current time and error for calc'ing the derivative next cycle lastTime = time0; preverror = error;*/ }
void SERIAL_PRINT(){
Serial.print(displacement); Serial.print(" , "); Serial.println(millis()); Serial.print(" ") ; }
/Users/RAJU/Documents/Documents/All Folders/Arduino 2017_v03_Maintable/Arduino-zero/DIS_SET_V04_Arduino-zero/DIS_SET_V04_Arduino-zero.ino: In function 'void READ_PHOTO()': DIS_SET_V04_Arduino-zero:144: error: 'ZeroFFT_input' was not declared in this scope ZeroFFT_input[2 * i] = analogRead(AOpin0); // Output of first half of photodiode array ^ /Users/RAJU/Documents/Documents/All Folders/Arduino 2017_v03_Maintable/Arduino-zero/DIS_SET_V04_Arduino-zero/DIS_SET_V04_Arduino-zero.ino: In function 'void DO_ZeroFFT()': DIS_SET_V04_Arduino-zero:186: error: 'ZeroFFT_reorder' was not declared in this scope ZeroFFT_reorder(); // Reorders the ZeroFFT_input array to allow the ZeroFFT_run() command to be used ^ DIS_SET_V04_Arduino-zero:187: error: 'ZeroFFT_run' was not declared in this scope ZeroFFT_run(); // This is the function that actually does the ZeroFFT ^ DIS_SET_V04_Arduino-zero:188: error: 'ZeroFFT_mag_lin' was not declared in this scope ZeroFFT_mag_lin(); // Produces a variable ZeroFFT_lin_out that contains the absolute values of the ZeroFFT, 128 elements long. ^ /Users/RAJU/Documents/Documents/All Folders/Arduino 2017_v03_Maintable/Arduino-zero/DIS_SET_V04_Arduino-zero/DIS_SET_V04_Arduino-zero.ino: In function 'void FIND_PEAK_INDEX()': DIS_SET_V04_Arduino-zero:196: error: 'ZeroFFT_lin_out' was not declared in this scope if (ZeroFFT_lin_out[i] > maxvalue) ^ /Users/RAJU/Documents/Documents/All Folders/Arduino 2017_v03_Maintable/Arduino-zero/DIS_SET_V04_Arduino-zero/DIS_SET_V04_Arduino-zero.ino: In function 'void PHASE_ANGLE()': DIS_SET_V04_Arduino-zero:217: error: 'ZeroFFT_input' was not declared in this scope Am = Am + float ((ZeroFFT_input[2 * i]) * cos(kmax * i)); //magnitude of real part ^ exit status 1 'ZeroFFT_input' was not declared in this scope /Users/RAJU/Documents/Arduino/libraries/Adafruit_Zero_FFT_Library/examples/mic_tft/mic_tft.ino /Users/RAJU/Documents/Arduino/libraries/Adafruit_Zero_FFT_Library/examples/normalized/normalized.ino
/Users/RAJU/Documents/Documents/All Folders/Arduino 2017_v03_Maintable/Arduino-zero/DIS_SET_V04_Arduino-zero/DIS_SET_V04_Arduino-zero.ino: In function 'void READ_PHOTO()':
DIS_SET_V04_Arduino-zero:144: error: 'ZeroFFT_input' was not declared in this scope
ZeroFFT_input[2 * i] = analogRead(AOpin0); // Output of first half of photodiode array
^
/Users/RAJU/Documents/Documents/All Folders/Arduino 2017_v03_Maintable/Arduino-zero/DIS_SET_V04_Arduino-zero/DIS_SET_V04_Arduino-zero.ino: In function 'void DO_ZeroFFT()':
DIS_SET_V04_Arduino-zero:186: error: 'ZeroFFT_reorder' was not declared in this scope
ZeroFFT_reorder(); // Reorders the ZeroFFT_input array to allow the ZeroFFT_run() command to be used
^
DIS_SET_V04_Arduino-zero:187: error: 'ZeroFFT_run' was not declared in this scope
ZeroFFT_run(); // This is the function that actually does the ZeroFFT
^
DIS_SET_V04_Arduino-zero:188: error: 'ZeroFFT_mag_lin' was not declared in this scope
ZeroFFT_mag_lin(); // Produces a variable ZeroFFT_lin_out that contains the absolute values of the ZeroFFT, 128 elements long.
^
/Users/RAJU/Documents/Documents/All Folders/Arduino 2017_v03_Maintable/Arduino-zero/DIS_SET_V04_Arduino-zero/DIS_SET_V04_Arduino-zero.ino: In function 'void FIND_PEAK_INDEX()':
DIS_SET_V04_Arduino-zero:196: error: 'ZeroFFT_lin_out' was not declared in this scope
if (ZeroFFT_lin_out[i] > maxvalue)
^
/Users/RAJU/Documents/Documents/All Folders/Arduino 2017_v03_Maintable/Arduino-zero/DIS_SET_V04_Arduino-zero/DIS_SET_V04_Arduino-zero.ino: In function 'void PHASE_ANGLE()':
DIS_SET_V04_Arduino-zero:217: error: 'ZeroFFT_input' was not declared in this scope
Am = Am + float ((ZeroFFT_input[2 * i]) * cos(kmax * i)); //magnitude of real part
^
exit status 1
'ZeroFFT_input' was not declared in this scope
/Users/RAJU/Documents/Arduino/libraries/Adafruit_Zero_FFT_Library/examples/mic_tft/mic_tft.ino
/Users/RAJU/Documents/Arduino/libraries/Adafruit_Zero_FFT_Library/examples/normalized/normalized.ino
